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x86: Add basic cache operations

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Add functions to enable/disable the data cache.

Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Stefan Reinauer 2012-12-02 04:49:50 +00:00 committed by Simon Glass
parent 9a7da182fa
commit 095593c030
4 changed files with 155 additions and 72 deletions
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38
arch/x86/cpu/cpu.c
View File

@ -34,6 +34,7 @@
#include <common.h>
#include <command.h>
#include <asm/control_regs.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#include <asm/interrupt.h>
@ -147,16 +148,27 @@ int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r")));
void x86_enable_caches(void)
{
const u32 nw_cd_rst = ~(X86_CR0_NW | X86_CR0_CD);
unsigned long cr0;
/* turn on the cache and disable write through */
asm("movl %%cr0, %%eax\n"
"andl %0, %%eax\n"
"movl %%eax, %%cr0\n"
"wbinvd\n" : : "i" (nw_cd_rst) : "eax");
cr0 = read_cr0();
cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
write_cr0(cr0);
wbinvd();
}
void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
void x86_disable_caches(void)
{
unsigned long cr0;
cr0 = read_cr0();
cr0 |= X86_CR0_NW | X86_CR0_CD;
wbinvd();
write_cr0(cr0);
wbinvd();
}
void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
int x86_init_cache(void)
{
enable_caches();
@ -200,3 +212,17 @@ void __reset_cpu(ulong addr)
generate_gpf(); /* start the show */
}
void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));
int dcache_status(void)
{
return !(read_cr0() & 0x40000000);
}
/* Define these functions to allow ehch-hcd to function */
void flush_dcache_range(unsigned long start, unsigned long stop)
{
}
void invalidate_dcache_range(unsigned long start, unsigned long stop)
{
}

68
arch/x86/cpu/interrupts.c
View File

@ -28,6 +28,8 @@
*/
#include <common.h>
#include <asm/cache.h>
#include <asm/control_regs.h>
#include <asm/interrupt.h>
#include <asm/io.h>
#include <asm/processor-flags.h>
@ -41,72 +43,6 @@
"pushl $"#x"\n" \
"jmp irq_common_entry\n"
/*
* Volatile isn't enough to prevent the compiler from reordering the
* read/write functions for the control registers and messing everything up.
* A memory clobber would solve the problem, but would prevent reordering of
* all loads stores around it, which can hurt performance. Solution is to
* use a variable and mimic reads and writes to it to enforce serialisation
*/
static unsigned long __force_order;
static inline unsigned long read_cr0(void)
{
unsigned long val;
asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order));
return val;
}
static inline unsigned long read_cr2(void)
{
unsigned long val;
asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order));
return val;
}
static inline unsigned long read_cr3(void)
{
unsigned long val;
asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
return val;
}
static inline unsigned long read_cr4(void)
{
unsigned long val;
asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order));
return val;
}
static inline unsigned long get_debugreg(int regno)
{
unsigned long val = 0; /* Damn you, gcc! */
switch (regno) {
case 0:
asm("mov %%db0, %0" : "=r" (val));
break;
case 1:
asm("mov %%db1, %0" : "=r" (val));
break;
case 2:
asm("mov %%db2, %0" : "=r" (val));
break;
case 3:
asm("mov %%db3, %0" : "=r" (val));
break;
case 6:
asm("mov %%db6, %0" : "=r" (val));
break;
case 7:
asm("mov %%db7, %0" : "=r" (val));
break;
default:
val = 0;
}
return val;
}
void dump_regs(struct irq_regs *regs)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;

16
arch/x86/include/asm/cache.h
View File

@ -32,4 +32,20 @@
#define ARCH_DMA_MINALIGN 64
#endif
static inline void wbinvd(void)
{
asm volatile ("wbinvd" : : : "memory");
}
static inline void invd(void)
{
asm volatile("invd" : : : "memory");
}
/* Enable caches and write buffer */
void enable_caches(void);
/* Disable caches and write buffer */
void disable_caches(void);
#endif /* __X86_CACHE_H__ */

105
arch/x86/include/asm/control_regs.h Normal file
View File

@ -0,0 +1,105 @@
/*
* Copyright (c) 2012 The Chromium OS Authors.
*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* Portions of this file are derived from the Linux kernel source
* Copyright (C) 1991, 1992 Linus Torvalds
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef __X86_CONTROL_REGS_H
#define __X86_CONTROL_REGS_H
/*
* The memory clobber prevents the GCC from reordering the read/write order
* of CR0
*/
static inline unsigned long read_cr0(void)
{
unsigned long val;
asm volatile ("movl %%cr0, %0" : "=r" (val) : : "memory");
return val;
}
static inline void write_cr0(unsigned long val)
{
asm volatile ("movl %0, %%cr0" : : "r" (val) : "memory");
}
static inline unsigned long read_cr2(void)
{
unsigned long val;
asm volatile("mov %%cr2,%0\n\t" : "=r" (val) : : "memory");
return val;
}
static inline unsigned long read_cr3(void)
{
unsigned long val;
asm volatile("mov %%cr3,%0\n\t" : "=r" (val) : : "memory");
return val;
}
static inline unsigned long read_cr4(void)
{
unsigned long val;
asm volatile("mov %%cr4,%0\n\t" : "=r" (val) : : "memory");
return val;
}
static inline unsigned long get_debugreg(int regno)
{
unsigned long val = 0; /* Damn you, gcc! */
switch (regno) {
case 0:
asm("mov %%db0, %0" : "=r" (val));
break;
case 1:
asm("mov %%db1, %0" : "=r" (val));
break;
case 2:
asm("mov %%db2, %0" : "=r" (val));
break;
case 3:
asm("mov %%db3, %0" : "=r" (val));
break;
case 6:
asm("mov %%db6, %0" : "=r" (val));
break;
case 7:
asm("mov %%db7, %0" : "=r" (val));
break;
default:
val = 0;
}
return val;
}
#endif